Cutting machine



July 13, 1948. w. R. SPILLER 2,445,243

CUTTING MACHINE Filed July 22, 1946 3 Sheets-Sheet 1 July 13, 1948. w.R. SPILLER CUTTING MACHINE 3 Sheets-Sheet 2 Filed July 22, 1946 July 13,1948. w. R. SPILLER CUTTING MACHINE 3 Sheets-Sheet 3 Filed July '22,1946 Patented July 13, 1948 I 2,445,248 cur'rmc momma William R.Spiller, Dayton, 'Ohio, assignor to Harria-Seybold Company, Cleveland,Ohio, a

corporation of Delaware Application July 22, 1946, Serial No. 685,429

15 Claims.

This invention relates to the operation and control of the clampingmechanism of paper cutting machines.

Machines used for cutting and trimming piles of paper of substantialthickness commonly employ a cutting knife mounted for vertical movementto and from cutting position and a clamp mechanism for holding the pilefirmly in proper position with respect to the knife. This clamp membermay be coupled with the drive mechanism for the knife for properlycoordinated action and high clamping pressure during the cutting cycle,and it is commonly provided with counterbalance means such as a springcounterbalance for automatically returning it to its inoperativeposition after the cutting stroke. In the operation of such machines, itis desirable for the movable clamp member to be brought into engagementwith the paper'in advance of the cutting cycle of the knife andindependently thereof, inorder to gauge the location of the out line,particularly with reference to printed stock, and insure properpositioning for cutting. This preliminary application of the clamp iscommonly carried out with relatively moderate pressure, usually no morethan sufllcient to express air from between the sheets in the pile andthus to aid in securing the proper position of the material for cutting.Thereafter the full clamping pressure is applied in conjunction with thecutting cycle of the knife.

In operation, the preliminary application of the clamping mechanism iscommonly initiated by means of a treadle or like externally operablemember independent of the main operating mechanism for the cutting cycleof the machine. If the connection to the clamp mechanism is such thatthe latter is operated by direct physical effort on the treadle, asubstantial force is required of the operator for satisfactoryoperation. Not only must the force of the counterbalance be overcome tobring the clamp into clamping position, but the necessary preliminaryclamping pressure must be developed. In some cases. it is necessaryduring this preliminary clamping action to exert suflicient force tocompress folded sheets adequately for accurate trimming. In addition,

'the clamp should be held in its preliminary clamping position until thecutting cycle of the machine begins, since if the clamp member isallowed to go up and thereafter descend in conjunction with the knife,there is a strong tendency for the pile' to shift upon the secondapplication of the clamp and to lose the desired alignment. It willaccordingly be seen that when the machine is so constructed that theclamp must be mechanically operated by physical effort on the treadle,the work is definitely fatiguing for the operator.

It is accordingly one of the principal objects of tive hydraulic systemfor operating the gauging mechanism of a paper cutting machine and whichmay be readily controlled by means of a simple treadle or like operatingmember.

An additional object is to provide a hydraulic operating system for theabove purpose wherein substantially the only force on the treadleto beovercome by the operator is the pressure of a spring which need be of nogreater tension than sufllcient to return the treadle to inoperativeposition when released.

It is also an object of the invention to provide for the full control ofthe preliminary movements of the clamping mechanism of a paper cuttingmachine in either direction, as well as over the pressure range capableof being exerted thereby, by simple manipulation of a treadle or likeoperating member with minimum physical effort on the part of theoperator.

A further object is to provide a servo mechanism for the preliminaryoperation of a clamping member as described above which includes a fluidpressure motor responsive to the introduction of hydraulic fluid tocause movement of the clamping mechanism and wherein movement of theclamp member in either direction may be controlled by adjustment of avalve member regulating the relative flow of hydraulic fluid to thefluid motor and by-passing the fluid motor.

A still further object is to provide a servo operating mechanism for theabove purpose which is self-contained and adapted for mounting as a uniton a paper cutting machine.

Other objects and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

In the drawings, in which like characters of reference designate likeparts throughout- Fig. 1 is a perspective view illustrating a papercutting machine provided with a hydraulic operating system for itsclamping mechanism in accordance with the present invention;

Fig. 2 is an enlarged front view of the hydraulic operating system forthe clamping mechanism of the paper cutting machine shown in Fig. l,with part of the front of the casing broken away and the internalmechanism shown in section substantially on the line 2-2 of Fig. 6;

. Fig. 3 is a side view, partly broken away, of the mechanism shown inFig. 2;

Fig. 4 is a fragmentary view in vertical section on the line H of Fig. 2and also of Fig. 6, showing details of the passages for the hydraulicfluid and the valve controlling these passages;

' lower end of this piston extends oiit'from the Fig. 5 is a fragmentaryfront view illustrating I the mounting for the treadle operatingmechanism shown in Fig. 2, the view being partially in section on theline 5-5 of Fig. 3;

Fig. 6 is a top view of the mechanism shown in Fig. 2, with the top ofthe casing and parts car-- ried thereby removed to show internalconstruction;

Fig. 7 is an enlarged and diagrammatic phantom view in perspective of apart of the cylinder block and casing shown in Fig. 2, to show the fluidpassages and other bores therein;

Fig. 8 is a fragmentary section similar to Fig. 4, but showing the valvemoved to a position wherein it causes actuation of the clamp member; and

Fig. 9 is a somewhat diagrammatic fragmentary section illustrating themovement of the piston and clamp operating lever in response tomovements of the valve as indicated in Fig. 8.

In the drawings, which illustrate a preferred embodiment of theinvention, the cutting machine shown in Fig. 1 includes a work table ladapted to receive the pile to be cut, as indicated at H, a. cuttingknife I2 mounted for shearing movement with respect to the work tablel0, and a clamp member l3 mounted closely adjacent the knife l2 forsimilar -vertical movement. In the operation of this cutting machine,the clamp is may be brought into initial clamping position in advance ofthe knife by actuating the threadle l at the front of the machine, thisposition of the clamp being indicated in dotted lines in contact withthe pile. This initial operation of the clamp need be only withsufflcient pressure to hold the paper firmly and to express air trappedbetween the individual sheets in the pile, thus enabling the operator tolocate the out lineon printed stock before the cutting cycle of themachine is begun. Thereafter the cutting cycle is initiated by asuitable actuating member, such as the lever l5, and full clampingpressure is exerted, and at the same time the knife is put through itscutting stroke by means of the links H, the power for this operationbeing supplied from motor I8 to the main drive shaft 20 through pulleys2i and 22 and belts 23. Suitable counterbalance mechanism such as springcounterbalances for the clamp are provided Within the cutting machineand serve to return it to the inoperative upper position as soon aspositive pressure is released for the return stroke. Members 25 in Fig.2 represent bearings for the crank shaft 26 positioned within thecutting machine shown in Fig. 1.

The mechanism of the invention for accomplishing the initial operationof clamp l3 as described includes a casing 30 bolted or otherwisesecured to the front of the cutting machine and having on its under sidea downwardly projecting yoke 32 in which a lever 33 is pivotally mountedby means of shaft 34 as shown in Figs. 2 and 3. The opposite end of thislever is connected to an upwardly extending arm 55 by means such as thedouble yoke 36. The upper end of arm 35 is in operative connection withclamp member 13 such that vertical movement of the arm will causesimilar movement of the clamping member.

To provide for such movement. a piston 40 is mounted for reciprocalmovement in a cylinder 4| formed in a block 42 integrally formed orotherwise secured within the interior of casing 30. The

casing through a packing chamber containing packing 43 held undercompression between a spring 44 and the outer angular cap 45. The lowerend of piston 40 and lever 33 are positioned for relative engagementsuch that downward movement of the piston will result in a downwardlyswinging movement of the lever about its pivot 34. In order to providefor minimizing friction between piston 40 and lever 33, a roller 48 ispivotally secured to the lever for engagement with the bottom face ofthe piston as shown particularly in Figs. 2 and 9. In accordance withthe invention, movement of treadle I5 is transmitted through a.hydraulic operating system to cylinder 4| and results in downwardmovement of piston 40, as viewed in Fig. 2, and a corresponding downwardmovement of lever 33 and arm to bring the clamp member l3 similarlydownward into its initial clamping position as described.

Casing 30 is largely hollow, as shown in Fig. 2, to provide a sumpcontaining a quantity of hydraulic fluid 50. A pump 5| has itsintake 52extending into the hydraulic fluid and is shown in Fig. 2 as mountedwithin the interior of casing 30 and operated through pulleys 53 and 54and belt 55 by motor 55 mounted at the top of casing 30. To provide forready adjustment of the ten sion of belt 55, motor 56 is pivotallymounted at one side, as shown in Fig. 3, by means of legs 51 on a. shaft58 carried by an upwardly projecting tongue member 59 on the top ofcasing II, and a jack screw 60 at the opposite side of motor 56 providesfor pivotal movement of the motor about shaft 58 to increase or decreasethe tension on belt 55. A housing Bl covers this belt drive and ismounted by means of a tie bar 62 on motor legs 51, this housing beingpartly broken out in Figs. 2 and 3 to show theinterior construction. Ailliing opening closed by a breather 63 at the top of casing 30 providesfor maintaining the fluid level within the casing, and a measuring stick54 is also indicated for measuring the level of fluid 50, which may fillthe casing approximately three-quarters full.

The outlet line 65 of pump 5! leads to a series of passages within thecylinder block 42, including a connection to cylinder 41 and a by-passof this connection. As shown in Figs. 4 and 8, the bore 66, shown asvertically arranged within the cylinder block, is connected at its upperend with the discharge line 65 from the pump and at its lower end leadsinto a transverse bore 61, which in turn leads to an additional bore 68opening back into the sump. As shown in Figs. 2 and 9, passage 10 abovebore 61 connects bore 56 with an opening 1| in the side of cylinder 4 I.

With this construction, when the connection between bores 66 and 61 isopen, the fluid pumped by pump 5] by-passes cylinder 4i and circulatescontinually through discharge line 65 and bores 66 and 51 to bore 68 andthen back into the sump. If this connection between bores 86 and 61 isclosed, the output of the pump will be forced into cylinder 4| toincrease the pressure therewithin and thus bring about motion of piston40 and clamp l3 as described.

The invention accordingly provides valve means for controlling the flowof fluid between bores 88 and 61 in response to movement of treadle l5to control the clamping mechanism. A valve stem 15 is mounted forsliding movement in bore 81 and is formed with one portion 18 of adiameter substantially equal to that of the bore, and an additionalportion 17 of reduced diameter. Thus when the portion 11 is in registerwith the bore I, there will be provided an adequate opening tor thehydraulic fluid around the valve portion 11 to permit continuouscirculation of the fluid by way of passages 68, 61 and 88 and thusprevent movement of the piston, these relative positions of the partsbeing indicated in Fig. 4. On the other hand, when the valve portion 18is in register with bore 6i. it will substantially block the latter boreas shown in Fig. 8 and thus force the output of the pump through thebore 10 into the cylinder 4| as described. Also, in order to provide forcontrolled passage of fluid from bore 68 into bore 01 at intermediaterates. valve portion 18 is notched at It, as shown in Figs. 4 and 8. toprovide a portion of progressively varying crosssectional areaintermediate the large valve portion It and the smaller portion 11. Theportion 18 at the end of valve stem I5 serves as a bearing for the valvestem in block 42 as shown.

In accordance with the invention the movement of valve stem to and fromthe various positions described is brought about through manipulation oftreadle l6, and the operating connections between these two parts areshown most clearly in Figs. 3 to 5. The treadle is secured to a shaft tocarried by trunnion members 8! and 82 extending downwardly irom thebottom of casing 30. The outer end 01 valve stem 15 is provided with apair or collars 83 one on each side of a yoke ll which is also securedto shaft 80. These connections are such that downward movement of thetreadle- I! will cause the valve stem I! to slide forward into thecylinder block and move the valve portions thereof from open to closedposition with respect to bore 86. A coil spring I! is mounted on shaftan in such position as to raise the treadle and return the valve stemand its valve portions to the open position when the treadle isreleased. These parts are covered in use by a shield 38, which is shownin Figs. 1 and 3 but is broken away in Fig. 2.

In the operation of the system, the normal position of the parts is asshown in Figs. 2 and 4, with valve stem IS in such position that itsvalve portion 'l'l of reduced diameter is in register with bore 86 topermit continuous circulation of the fluid 50 through these bores,by-passing cylinder 4 l. Under these conditions, clamp member I! is heldin its uppermost position by its counterbalance mechanism, thus holdingarm 35, lever 33 and piston 40 in their uppermost positions as shown inFig. 2. When it is desired to operate the clamp mechanism, treadle i5 isdepressed against the action or spring 86, and valve stem-ll slidesinwardly until its valve portion 18 closes bore 68. Since pump Si isoperating continuously, this will iorce the fluid from its dischargeline I to enter cylinder 41 through bore 10 and opening H and therebyincrease the pressure within the cylinder sufllciently to move piston40. The piston will accordingly move downwardly as shown in Fig.0, andwill thereby force lever 38 to swing about its pivot 34 and to draw downarm 35 and the clamp member It as indicated in dotted lines it is merelynecessary to remove pressure from will thus draw arm 35, lever 33 andpiston 40 back again to their uppermost positions.

In order to avoid development 0! excessive pressure when the piston andclamp are. prevented i'rmn moving by engagement with the work, whichposition it may be desirable to retain for a period 0! time, a reliefvalve is provided within the cylinder block. As shown in Figs. '4 and 8,a bore connects bores l8 and I, and its connection with bore I. iscontrolled by a ball valve ti and spring 92. This spring may be set fora predetermined pressure, ior example 400 pounds per square inch, andwhen the pressure within the cylinder reaches this value, the springwill be overcome to permit the fluid to resume circulation through bores8, l0 and 88 while still maintalning the clamp in clamping position.With a piston of a diameter of 1 inches, this construction will providea force oi 700 to 750 pounds eflective on lever 33 and a net pressureavailable on the pile ofv between 200 and 250 pounds, as compared withfull clamping pressure of the order of one or more tons exerted duringthe cutting cycle of the machine.

The above construction provides also for controlling the rate at whichthe clamp member moves as well as for stopping it in any desiredposition and controlling its pressure within the maximum rangedetermined by the setting of the spring I: for the relief valve. Thus,if valve stem II is moved in only part way, such that the slotted valveportion I8 is in register with bore #6, the pressure within cylinder 4|may be regulated to provide for slow movement of the piston in eitherdirection or for stopping the piston and clamp in any desired position,by adjustment of the valve, such that the fluid escapes through slots 18at a pressure just equal to the pressure of the counterbalance for theclamp member. Similarly, when the clamp is restrained from moving, thepressure exerted thereby maybe varied by adiustment oi the valve topermit slow escape of fluid through slots 18 at a rate such that thepressure is maintained below the maximum at which the relief valve inbore on will open. Thus by variation of the position of the valve stem15 under control of the treadle, the effective pressure of the clamp onthe pile, as well as its upward and downward movement, are undercontinuous and accurate control.

The invention accordingly provides for the simple and eflective movementor the clamping mechanism of a paper cutting machine with minimumphysical effort on the part of the operator. The above described andillustrated hydraulic system provides both for movement of the clampingmechanism independently of the main operating mechanism of the machineand also for full control and adiustmentoi the clamping mechanism,including stopping and starting at any point, direction of movement anddegree 0! pressure exerted. This control and adjustment is obtained inaccordance with the invention by simple manipulation of the treadle,which requires no greater force than is necessary to overcome the springpressure returning the treadle to'its inoperative position whenreleased, there being substantially no resistance to the movement of thevalve controlling the flow or hydraulic fluid as described in responseto treadle movement. Accordingly the physical efl'ort required on thepart or the operator may be considered as virtually negligible,particularly as compared with the corresponding effort neededfor'operation of the clamp member by mechanical connection with thetreadie, which in addition does not aflord comparable flexibility orcontrol.

1 While the form of apparatus herein described constitutesa preferredembodiment oi the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and

. inary operation of said clamp member independently of the mainoperating mechanism of said machine and comprising, in combination, 9,cylinder and piston mounted for relative movement in response to fluidpressure within said cylinder, means efl'ective upon relative movementof said of said fluid therethrough and being effective in anotherposition to close said Icy-pass and to supply said fluid under pressureto said motor, and means limiting the maximum fluid pressure supplied tosaid motor.

4. In a cutting machine of the character described having a clamp memberfor clampin work material to be cut and for gauging the out line on saidmaterial, means for the preliminary operation of said clamping memberindependently oi! the main operating mechanism 01' said machine andcomprising, in combination, a fluid pressure motor mounted on saidmachine, means providing a connection between said motor and piston andcylinder to cause clamping movement of said clamp member, means forproviding a supply of hydraulic fluid under pressure, means forming apassage for supplying said pressure fluid to said cylinder, meansforming a by-pass passage for said fluid by-Dassing said cylinder, valvemeans controlling the flow of said pressure fluid through said by-pass,means limiting the maximum pressure developed within said cylinder, andexternally operable means controlling the movement of said valve means.

2. In a cutting machine of the character described having a clamp memberfor clamping work material to be cut and for gauging the cut line onsaid materiaL-means for the preliminary operation of said clampingmember independently of the main operating mechanism or said machine andcomprising, in combination, a cyl-- inder and piston mounted forrelative-movement in response to fluid pressure within said cyilnder,

means effective upon relative movement of said piston and cylinder tocause clamping movement of said clamp member, means for containing asupply 01 hydraulic fluid, means forming a pas- ,sage for conveying saidpressure fluid to said cylinder,v means forming a by-pass passage forsaid fluid by-passing said passage to said cylinder, mean providing forthe circulation of said fluid under pressure through said passage, valvemeans controlling the relative flow of said fluid to said cylinder andthrough said by-pass, means limiting the maximum pressure developedwithin said cylinder, and externally operable means controlling movementof said valve means.

3. In a cutting machine of the character describedhaving a clamp memberfor clamping work material to be cut and for gauging the out line onsaid material, means for the preliminary operation of said clampingmember independently of the main operating mechanism of said machine andcomprising, in combination, a fluid pressure motor, means providing aconnection between said motor and clamp member eflectlve to causeclamping movement of said clamp member upon the application of fluidpressure to said motor, means for containing a supply of hydraulicfluid, means forming a passage for supplying said pressure fluid to saidmotor, means forming a by-pass passage for said fluid bypassing saidpassage to said motor, means providing for the circulation of said fluidunder pressure through said passages, valve means controlling therelative flow of said fluid to said motor and through said by-pass,externally operable means controlling movement of said valve means, saidvalve means being effective at one position to open said by-pass forcontinuous circulation said clamp member effective to cause clampingmovement of said clamp member in response to the application of pressureto said motor, means for containing a supply or hydraulic fluid, meansforming a passage for supplying said pressure fluid to said motor, meansforming a by-pass passage for said fluid by-passing said passage to saidmotor, means providing for the circulation of said fluid under pressurethrough said passages, valve means controlling the relative flow of saidfluid to saidmotor and through said by-pass. and externally operablemeans controlling movement 01' said valve means, said valve means beingeffective in one position to open said by-pass for continuouscirculation of said fluid therethrough and being. eflective in anotherposition to close said by-pass and to simply said fluid under pressureto. said motor, said valve means being effective in a third position toopen said by-pass partially Ior restricted passage of said fluidtherethrough.

5. In a cutting machine of the character described having a clamp memberfor clamping work material to be cut and for gauging the out line onsaid material, means for the preliminary operation of said clampingmember independently oi .the main operating mechanism of said ma- Ichine and comprising, in combination, a fluid pres-sure motor, meansproviding-a connection between said motor and said clamp memberefl'ective to cause clamping movement of said clamp member in responseto the application of fluid pressure to said motor, means for containinga supply of hydraulic fluid, means forming a passage for supplying saidpressure fluid to said motor, means forming a by-pass passage for saidfluid by-passing said passage to said motor, means providing for thecirculation or said fluid under pressure through said passages, a valvemounted for sliding movement substantially transverse to said by-pass tocontrol the flow of said fluid therethrough, said valve being effectivein one position to open said by-pass for the continuous circulation ofsaid fluid therethrough and being effective in another position to closesaid by-pass and to supply said fluid under pressure to said motor, andmeans limiting the maximum fluid pressure supplied to said motor.

6. In a cutting machine of the character described having a clamp memberfor clamping work material to be cut and for gauging the cut line onsaid material, means for the preliminary operation of said clampingmember independently of the main operating mechanism of said machine andcomprising, in combination, a cylinder and piston mounted for relativemovement in response to fluid pressure within said cylinder, meanseffective upon relative movement of said piston and cylinder to causeclamping movement of said clamp member, means for containing a supply ofhydraulic fluid, a pump having its intake adapted for connection withsuch supply or fluid, means forming apassage leading trom the outlet orsaid pump/intosaid supply of fluid and providing for continuouscirculation thereof, a valve control-' said pump for-supplying saidfluid to said cylinsition to der, said valve being eflective in one opensaid passage for continuous circ on of said fluid therethrough under theaction said pump and being eflective in another position to close saidby-passv and thus to cause said fluid to enter said cylinder underaction or said pump, pressure relief means for preventing the pressurewithin said cylinder from exceeding a predetermined maximum, andexternally operable means controlling movement or said valve.

"I. In a cutting machine oi the character described having a clampmember for clamping work material to be cut and for gauging the cut lineon said material, means tor the preliminary operation ,or said clampingmember independently or the main operating mechanism of said machine andcomprising, in combination, a cylinder and piston mounted for relativemovement in response to fluid pressure within said cylinder, meanseffective upon relative movement of said piston and cylinder to causeclamping movement of said clamp member. means for containing a supply ofhydraulic fluid, a pump having its intake adapted for connection withsuch sup ply of fluid, means forming a passage leading from the outletof said pump, back to said supply of fluid and providing for thecontinuous circulation thereof, a valve for controlling the flow ofliquid through said passage and mounted for sliding movement at an angleto said passage, a connection between said passage and; said cylinderpositioned between said valve and the outlet said pressure fluid throughsaid by-pass, said valve means being eflective in one position to opensaid by-pass tor the passage of said fluid therethrough and beingeffective in another position to close said by-pass and to cause saidmud to" enter said cylinder and to move said piston therein.

,9'. In a cutting machine of the character. described having' a clampmember ior clamping work material to be cut .and ior gauging'the outline on said material. means for the preliminary operation of saidclamping member independently or the main operating mechanism 01' saidmachine and comprising, in combination, a. cylin-, der, a piston mountedfor movement in said cylinder in .response to fluid pressuretherewithin,"

means including a lever for "causing operative movement of said clam'pmember, means mounting said lever for pivotal movement in the plane ofmotion or said piston and adjacent thereto, roller means carried by saidlever and engage able by said piston upon motion thereof in saidcylinder to cause pivotal movement'oi said lever, means for containing asupply or hydraulic fluid, means iorming a passage for conveying saidpressure fluid to said cylinder, means forming a bypass passage for saidfluid by-passing said passage to said cylinder, means providing for thecirculation of fluid from said container under pressure through saidpassages, and a valve consaid by-pass and to cause said fluid to entersaid of said pump for supplying said fluid to said cylinder, said valvebeing eflective in one position to open said passage for continuouscirculation or said fluid therethrough and in another position to closesaid passage and thus to cause said fluid to enter said cylinder underthe action of said pump, said valve in an intermediate position beingeffective to open said passage partiall for restricted circulation orfluid therethrough to establish an intermediate pressure within saidcylinder for con-trolling the operation of said pump, and pressurerelief means for preventing the pressure within said cylinder'fromexceeding a predetermined maximum.

8. In a cutting machine of the character described having a clamp memberfor clamping work material to be cut and for gauging the out line onsaid material, means for the preliminary operation of said clampingmember independently of the main operating mechanism of said machine andcomprising, in combination, a cylinder,

' a piston mounted for movement in said cylinder cylinder under pressureand to bring about movement of said piston and lever, said valve in anintermediate position being eflective to open said by-pass partially forrestricted passage or said fluid therethrough to establish anintermediate pressure within said cylinder to control the oper ation ofsaid clamp.

10. In a cutting machine or the character described having a clampmember for clamping work material to be cut and for gauging the cut lineon said material, means for the preliminary operation of said clampingmember independently of the main operating mechanism of said machine andcomprising, in combination, a fluid pressure motor, means providing aconnection between said motor and said .clamp member eftective to causeclamping movement 01 said clamp member upon the application of pressurefluid to said motor, means for containing a supply or hydraulic fluid, apump having its intake positioned for connection with such supply offluid, means forming a passage leading from the outlet of said pump backto said container for fluid and providing for continuous circulation offluid, said passage including'two angularly arranged connectingportions, a valve mounted for sliding movement in one of said angularlyarranged pas sage portions adjacent the Junction between said portions,a connection between said passage and said motor positioned betweensaidvalve and the outlet of said pump'for supplying said pressure fluidto said motor, means limiting the maximum fluid pressur supplied to saidmotor, said valve including portions of different cross-sectional areaand being effective in one position to close communication between saidangularly arranged passage portions to supply said fluid to said motorunder the action of said pump, said valve being effective in anotherposition to open said pas- 11' sage for continuous circulation of saidfluid therethrough.

11. In a cutting machine of the character described having a clampmember for clamping work material to be cut and for gauging the out lineon said material, means for the preliminary operation of said clampingmember independently of the main operating mechanism of said machine andcomprising, in combination, a cylinder and piston mounted for relativemovement in response to fluid pressure within said cylinder, means forcontaining a supply of hydraulic fluid, a pump having its intakepositioned for connection with such supply of fluid, means forming apassage leading from the outlet of said pump back to said container forfluid and providing for continuous circulation of fluid, said passageincluding two angularly arranged connecting portions, a valve mountedfor sliding movement in one of said angularly arranged passage portionsadjacent the Junction between said portions, a connection between saidpassage and said cylinder positioned between said valve and the outletof said pump for supplying said pressure fluid to said cylinder, saidvalve including portions of diflerent cross-sectional area and beingeffective in one position to close communication between said angularlyarranged passage portions to cause said fluid to enter said cylinderunder the action of said pump, means limiting the maximum pressuredeveloped within said cylinder, said valve being eilectivein anotherposition to open said passage for continuous circulation of said fluidtherethrough, said valve in an intermediate position being effective topermit restricted circulation of said fluid through said passage.

12. In a cutting machine of the character described having a clampmember for clamping work material to be cut and for gauging the out lineon said material, meansfor the preliminary operation of said clampingmember independently oi' the main operating mechanism of said machineand comprising, in combination, a casing secured to said machine andadapted to contain a supply of hydraulic fluid, means providing acylinder carried by said casing, a piston mounted in said cylinder forrelative movement in response to fluid pressure within the cylinder,pressure relief means for preventing the pressure within said cylinderfrom exceeding a predetermined maximum, a pump having its intakeconnected with said supply of fluid, means forming a passage leadingfrom the outlet of said pump back to said supply of fluid within saidcasing and providing for continuous circulation of said fluid, a valvecontrolling the flow of said fluid through said passage, means providinga connection between said cylinder and said passage positioned betweensaid valve and the outlet oi said pump, said valve being effective inone position to close said passage to cause said fluid to enter saidcylinder under the action of said pump and being effective in anotherposition to open said passage for continuous circulation of said fluidtherethrough, a lever pivotally secured to said casing for swingingmovement about a substantially horizontal axis, and an arm connected atone end to said lever and at the other end to said clamp member formoving said clamp member vertically in response to swinging motion ofsaid lever, said lever being positioned for operative engagement withsaid piston and being adapted to be swung downwardly upon movement ofsaid piston in response to fluid pressure within said cylinder.

13. A servo mechanism for operating the mo able clamp member of a papercutting machine, comprising, in combination, a fluid pressure motormounted on said machine, means providing a connection between said clampmember and said motor effective to cause clamping movement of said clampmember upon the application of pressure fluid to said motor, means forcontaining a supply of hydraulic fluid, means including a pump and apassage by-passing said motor for circulating fluid from said container,a valve controlling the flow of said fluid through said bypass, meansforming a passage connecting said motor with said by-pass and openinginto said bypass at a position between said valve and the outlet of saidpump, said valve being efiective in one position to open said by-passfor continuous circulation of said fluid therethrough and beingeffective in another position to close said bypass and to cause saidfluid to be supplied to said motor under the action of said pump, andmeans limiting the maximum fluid pressure supplied to said motor.

14. In a paper cutting machine of the charac-,

ter described, the combination of a work table, a, clamp member mountedfor relative movement with respect to said work table for clamping workmaterial to be cut, a casing mounted on said machine at a position belowsaid work table, a cylinder within said casing, a piston mounted forrelative vertical movement in said cylinder in response to fluidpressure within said cylinder, means including a lever providing aconnection between said piston and said clamp member effective to causeclamping movement of said clamp member upon outward movement or saidpiston from said cylinder, said connection means being independent ofthe main' operating mechanism oi. said machine, said casing beingadapted to contain a supply of hydraulic fluid, a pump mounted withinsaid casing, means including a passage icy-passing said cylinder andcooperating with said pump for circulation of said fluid within saidcasing, means forming a passage for supplying said fluid to saidcylinder, relief valve means for controlling the pressure developedwithin said cylinder, valve means controlling the relative flow of saidfluid through said passage and said by-pass, and externally operablemeans controlling the movement of said last named valve means.

15. In a paper cutting machine of the character described having a worktable and a clamp member mounted for relative movement with respect tosaid work table for clamping work material to be cut,- operating meansfor said clamp member comprising, in combination, a casing adapted to bemounted on said machine, a fluid pressure motor within said casing, saidcasing being adapted to contain a supply of hydraulic fluid foroperating said motor, means providing a connection between said motorand said clamp member eiTective to cause clamping movement of said clampmember upon the application of pressure fluid to said motor, meanswithin said casing for supplying such hydraulic fluid under pressure tosaid motor, control means for regulating the flow of such fluid to saidmotor, means limiting the maximum fluid pressure supplied to said motor,and externally accessible means carried by said casing for actuatingsaid control means for the operation of said clamp member.

WILLIAM R". SPILLER.

. A Gertlleate of Correction 7 Patent No. 2,445,248. July 13, 1948.WILLIAM .R. SPILLER It ishereby certified that errors appear in theprinted specification of the above numbered patent reqluniringcorrection as follows: Column 7, line 46, claim 2, for mean read means;e 47, for passage read. panties and that the said Letters Patent shouldbe read with these corrections therein at the sanre may conform to therecord of the case in the Patent Oflice Signed and sealed this 26th dayof Oetobenh. D. 1948.

I THOMAS F. MURPHY, I

Am'etmt Gommzuiomr of Patents.-

